Although I am not a resto shaman (I spec ele) it seems that shamans have a great deal of difficulty in movement based fights that 15 seconds of "cast on the move" doesn't seem to solve and thus creates even more difficulties for healers that don't have Oh S**t buttons. Perhaps Blizz could alter Spirit Walkers Grace (through a resto talent or glyph) that treats it like Blade Flurry for combat rogues and allows shamans to toggle it on and off with a CD and a penalty of some sort such as increasing the mana cost, spells no longer benefit from haste, etc.

This would:
1) give shamans a unique mechanic and play style with no real duplication from other healing classes
2) substitute for a traditional cooldown (or it could be considered a throughput increase since there would be less interruptions to casting)
3) allow Blizz to tweak an already existing spell rather than create a new one

I really like spirit walkers grace and I wish that changes could be made to make it more viable as an actual CD. Or they could just give us back Spirit Link lol

I like your idea of modifications to Spiritwalker's Grace, but I don't think it comes under the heading of defense cooldowns that the article's talking about. (Unless we're talking about giving shamans a unique niche INSTEAD of these cooldowns. Which is actually an interesting thought, but unlikely to happen given that Bliz is currently working towards 'bring the player, not the class'.)

How about a complete redo of Spirit Link? Instead of linking the person to one or more other people which was apparently too hard to balance (/sigh), a spirit wolf/ancestor/water-elemental would appear and the person would be Spirit Linked to THAT instead. As long as the spirit creature was there, maybe 10 seconds or so, the person would take reduced damage. A slight variation on this would be that the person is actually SHIFTED INTO the spirit world briefly, reducing damage taken in the physical world.

Another possibility is the ultimate ability that the Shadow Hunter Rokhan used in WCIII. From what I remember, he could surround himself with a large buzzing cloud of spirits that would drain life from nearby enemies and transfer it to Rokhan. Perhaps shaman could use a reworked version of Voodoo Spirits: putting it on (for example) the tank, and instead of the tank taking reduced damage for 10 seconds, he would be actively healed by the spirits buzzing around him.

Why not just make Spiritwalkers Grace an ability that is a toggle. You have the toggle on and if you move while casting, then it uses it up, turns the toggle off and you have to wait until the cooldown is up to toggle it back on. This makes the ability less like a trinket and more like an cool ability.